The present invention relates to a keypad device for telephones, mobile phones, remote control units, text and character transmitters, calculators, electronic planners or the like, wherein a control element, when actuated manually by an operator""s finger, is adapted to carry out at least two function commands, and wherein various positions of the control element are identified by means of optical detectors.
The use of a plurality of keys or multifunction keys is previously known, inter alia, in connection with mobile telephones. These keys are operated by the user depressing them. As a rule, these known function keys are connected to microswitches, and there is thus only a limited number of functions that are possible with one and the same key without rendering the functionality complex and difficult to use. It is also known that microswitches have as a rule an imprecise activation characteristic. Today""s mobile phones contain a profusion of functions in addition to ordinary telephone functions and they are equipped with a memory like that in small computers. This allows a user to compile information, e.g., telephone number and address lists. The further development has tended towards mobile phones which are built up as complete communicators for text, video and voice by using, for example, the Internet which is normally used on a PC. A new format for this is called WAP and it is a standard for Internet services for GSM telephones. All these new services and functions will require simpler, logical and efficient methods of operation and navigation as a standard button keypad. Obviously, a standard button keypad will require a very great number of buttons in order to be able to serve so many functions, and as a result will at the same time become difficult or awkward to use, and not least bulky. With the ever-increasing tendency towards miniaturisation there have been limitations, particularly in connection with mobile phones, with respect to how small function keys can be made without creating problems as regards the operation of the keypad.
U.S. Pat. No. 4,994,669 discloses a device of the joystick type in which the various positions thereof are identified by means of a set of light emitters and light receivers, the control element of the device being of a type that can not be depressed.
The object of the present invention is thus to provide a device wherein at least two, but preferably a great number and range of functions can be effected using one and the same key, where the user can use the device for different apparatuses, preferably mobile phones, in a simple, logical and reliable manner, in order to operate effectively through functions and menus, whilst during simple operations, such as using a mobile phone (e.g., dialling a number), not being dependent upon monitoring the device visually. Consequently, it is also an object of the invention to enhance the MMI, i.e., Man-Machine Interface.
The characterising features of the device according to the preferred embodiments are set forth in the characterising clauses of attached claims 1, 6, 13, 14, 15, 45, 53, 54, 60, 61, 67, 69, 72, 74, and 76, and the appurtenant subclaims.